Which has no part in the scientific method of experimentation?

Assumption has no formal part in the scientific method of experimentation. Scientific investigation typically uses observation, hypothesis formation, prediction, experimentation, data analysis, and a conclusion.

An assumption is an untested belief accepted temporarily or taken for granted. Scientists may make practical assumptions when designing a study—for example, that an instrument is calibrated or that conditions remain stable—but those assumptions are not themselves steps in the method and must not replace evidence.

The method became central during the Scientific Revolution of the 16th and 17th centuries. A hypothesis proposes a testable explanation, while an experiment produces observations or measurements that can support, refine, or reject it. A common mix-up is treating a hypothesis as an assumption: a hypothesis is an explicit, falsifiable proposal that must face testing.

Scientific methods are not always a fixed checklist. Different fields may use observational studies, simulations, statistical analysis, or controlled experiments, but each relies on empirical evidence and critical evaluation rather than unsupported assumptions.